0000000016 00000 n ... La riduzione dei rifiuti conferiti in discarica, unitamente all'attuazione di un sistema integrato e moderno di gestione di rifiuti urbani e assimilati, costituisce uno degli aspetti chiave del decreto "Sblocca Italia", che riprende quanto indicato nel VII Programma d'Azione UE [7]. and limit our current ability to develop such strategies. Ultimately, natural petroleum resources can be conserved by recycling waste products which leads to the sustainable development of novel products. Glasswool was placed in the bottom of, on and inside the bed in order to separate the catalyst and the, s 17 min and the reaction temperature 450, . Uddin A., Koizumi K. and Sakata Y., (1997). For thermal degradation, both HDPE and XLPE produced a significant amount of wax-like compounds and the yields of liquid products (58–63 wt%) were lower than that of LDPE and LLDPE (76–77 wt%). The leachate quality from the ash cover is expected to have a minor influence on overall landfill leachate quality because the amounts generated from the ash covers were low, <3-30l (m(2)yr)(-1). 3) Biocompatibility of the nanocomposites Since the duration of life of plastic wastes, . 44 32 Catalytic degradation of LDPE over micrometer and nanocystalline HZSM-5 zeolites generated a similar range of degradation products with a marked increase in the light olefins and aromatic fractions (e.g. A dissolution/reprecipitation process has been developed for recycling low density polyethylene. In the present investigation the recycling of LDPE, HDPE and PP was examined using two different methods: the dissolution/reprecipitation and pyrolysis. Results allow to conclude that the content that showed the best results was 15% of PET because its compressive strength showed a value greater than the others, highlighting even lower absorption, resulting from its higher homogeneity and better wrapping of the obtained composite. The pyrolysis products contained about 36% ethene, 15% propene, 9% 1-butene and butadiene and an additional 15% pyrolysis gasoline. trailer As a result, PVC requires separation from other plastics before mechanical recycling. This Special Issue is planned to bring together a number of original papers and reviews covering (but not restricted to) the following topics: Further investigation was focused on the effect of sample history through successive recycling cycles. polypropylene. RECYCLING TECHNIQUES OF POLYOLEFINS FROM PLASTIC WASTES pyrolysis of plastic wastes gives valuable products similar to diesel and gasoline [6]. 0000090035 00000 n commercial waste products (packaging film, different experimental conditions and for a, DSC. This result clearly shows the importance of the polymer state during each temperature stage. In advance, and after recycling, were measured and are illust, was observed between the values measured before and after recycling for all model polymers, and waste samples. Cracking of, Finally, the compounds identified in the liquid fr, mixture of hydrocarbons was determined for all, with only a small proportion of aromatic subs, pyrolysis temperature. The science and technology of The details of the course are: course code (PL8074), Category (PE), … Addition polymers (like polyethylene) in, ers (i.e. The recyclable materials were in many cases exported to other countries which made it difficult to track their destination and further treatment. 4) Biodegradation of the nanocomposites, nanocomposites or multifunctional polymers, have redefined the need for a thorough theoretical or experimental study of the polymerization kinetics. Moldovan, A., et al. An enormous amount of computer wastes are either landfilled or incinerated, which results in leaching of chemicals and emission of toxic gases respectively. The chromatograp. 0000076673 00000 n For this purpose different solvents/non-so, percent amounts and temperatures using either model polymers as raw material or. 11 This plastic can be sorted into main streams of polypropylene (PP), high‐density polyethylene (HDPE), low‐density polyethylene (LDPE), PET and polystyrene (PS) using a series of rotary screen drums, near‐infrared sorting and washing steps. Bulky waste quantities and treatment methods in Denmark, Assessing the environmental impact of ashes used in a landfill cover construction. Zeolites of the kind employ, feedstocks (Y, ZSM-5, Beta) as well as other, catalysts takes place through the formation of ca, the performance of acid solids in the catalytic, characteristics and particle size determine to, polymeric molecules to the internal catalytic ac, HZSM-5 presents bigger reactivity from HMCM, decomposition of the large molecules of PP the transformation is al, thermal cracking, because cross-section of polymer, In the present investigation, the chemical, using two different methods: the traditional meth, challenging technique of pyrolysis. Biocomposites were reprocessed 5 times using the extrusion process followed by injection molding. Thus, talysts allows the process to be directed towards the formation, investigated extensively using solids with, ed in the catalytic cracking of hydrocarbon. It includes: (a) direct recycling to virgin plastic (i.e. A major problem in the recycling of PVC is the high chlorine content in raw PVC (around 56 percent of the polymer's weight) and the high levels of hazardous additives added to the polymer to achieve the desired material quality. 44 0 obj<> endobj Significant knowledge and data gaps associated with the fate of ENMs incorporated in consumer products in waste management processes (e.g., landfilling, incineration, recycling) exist, Bulky waste is a significant and increasing waste stream in Denmark. One of the most common recycling processes used is extrusion blow moulding. %PDF-1.4 %���� These complex materials, represented sche-matically in Fig. This mixture feeds 3 lines of depolymerization (Syntrol®), which are reactors operating at increasing temperatures lower than 400° C. The presence of 2 alkaline scrubbers and 1 alkaline scrubber guarantees the absence of dioxins and furans in exhaust smoke. Full-text available. A method of recycling mixed post-consumer plastics waste includes the steps of providing mixed post-consumer plastics waste including polyolef in and non-polyolefin components, and melt-compounding the waste so as to form a continuous phase including a blend of the polyolefin components with the non-polyolefin components microdispersed therein. Then, the flask was cooled and the, into the non-solvent. and Papaspyrides, C.D., (1995), The. As recycling methods for PP, the following are known-primary recycling, mechanical (secondary recycling), chemical and pyrolysis methods [17][18]. The concept of utilizing filler materials to enhance polymer performance in Composite materials has drawn a great deal of research interest. It allows the treatment of mixed, unwashed plastic wastes. Remedies to the challenges on Plastic waste recycling in Uganda There is need to encourage the minimization, reuse and recycling of plastic wastes by all solid waste producers. Plastic recycled by Top Recycling comes from : Production scraps; Particularly for the thermoforming activity Non-hazardous industrial wastes; Non-hazardous & non-polluted industrial wastes (example : plastic cores) Non-polluted manufacturing wastes; example : purges of injection molding) Scraps : Liquid fuel oil is rich in paraffins and olefins containing C 8-C 24 hydrocarbons. This highlights the urgent need for scrutiny in the way plastics are designed, produced, used, and managed, to better understand how to improve their ability to circulate back into the system, recovering maximum value from them. Polyolefins, mainly polyethylene (LDPE or HDPE) and polypropylene (PP) are a major type of thermoplastic used throughout the world in a wide variety of applications. Porosity, surface area, a large extent the accessibility of bulky, id sites of the solids. However, only little research has been done on its composition and treatment. In some pyrolysis experiments, ymers. Therefore, recycling either mechanical or chemical, seems to be the only route of plastic wastes management towards sustainability. For this it was made an experimental analysis replacing, in volume, fine aggregate (fine crushed stone) by fractions of crushed PET in contents of 15%, 30% and 45%. The liquid oil product was analyzed by GC/MS technique. The recycled grades were evaluated in terms of the following properties: melt flow index (MFI), molecular weight, crystallinity, mechanical performance in tensile mode, and grain size analysis. This work shows the analysis of a no conventional element for building sealing system: a pressed concrete block incorporating recycled PET. Article. This paper covers the recent research carried out by the authors on the chemical recycling of poly(ethylene terephthalate) (PET) taken from post-consumer soft-drink bottles. With silica-alumina, all of the polyethylenes were converted to liquid products with high yields (77–83 wt%) and without any wax production. Pyrolysis seem, in an oil and gaseous product. It was also observed that the, very much dependent on the type of polymer, was observed in PP, followed by LDPE and finally HDPE. Indicative spectra for PP bas, Comparing the FT-IR spectra of the solid obtaine, recovered with this technique. It, much dependent on the polymer type, as it is, e composition of the gaseous fraction, in all, . Clark), Cambridge. Association, 2007, Association of Plastic Manufacturers, 2007). The article introduces an innovative system able to recycle a portion of plastics generally The choice of recycling of waste thermoplastics depends on processing equipment such as injection, single-screw extruder and film blowing machine, and processing conditions (temperature, time, content of materials, and rheological behavior) and product uses [27][28][29]. The instrument used was an FTIR spectrophotometer of Perkin-Elmer, Spectrum One. Disposing of plastic wastes to landfill is becoming undesirable due to legislation pressures, rising costs and the poor biodegradability of commonly used polymers. In the USA, about 30 million tons of plastic wastes were produced in 2009 and only about 7% was recycled. polymer (1 gr) and the solvent (20 ml) were, temperature. <]>> The effect of the heating program on the liquid product quality and distribution is also investigated, using two different temperature programs with the same levels of temperature steps, but different duration. leaching of substances from a full-scale landfill cover test area built with different fly and bottom ashes was evaluated based on laboratory tests and field monitoring. 0000004396 00000 n toluene) in place of xylene did no, contrast, lower amounts of polymer were recovered in some experiments. 0000005502 00000 n The, hexane) were reagent grade. 1 Introduction to Feedstock Recycling of Plastics (A. Buekens). The rheological test shows that viscosity values of PP and biocomposites decrease progressively with extrusion cycles; however, Cole-Cole plots, dynamic mechanical analysis (DMA), width at half maximum of tan delta peaks and SEM micrographs show that chemical treatments and reprocessing could improve fiber dispersion and fiber-matrix interaction. The solvent mixtures involved are separated by distillation for further reuse. Plastic sorting equipment Sorting of plastics from packaging, separate collection, commercial waste and from production residues for material recycling In Europe, almost 50 million tonnes of plastics are required each year for the widest range of applications and brought into the product cycle. for recycling of waste polymers include (Scheirs, 1998; Achilias and Karayannidis, 2004): monomers, or partial degradation to other secondary valuable materials. The purpose of this workshop - held at the 16th International Waste Management and Landfill Symposium, Sardinia 2017, S. Margherita di Pula, Italy - was to highlight: (1) currently existing knowledge associated with ENM fate in waste management processes, (2) potential implications associated with ENM disposal, (3) challenges associated with conducting ENM-based research in waste environments, and (4) research needs. PET and compared with previous results on the alkaline hydrolysis of PET with, or without, the use of a phase transfer catalyst. One approach for recovering individual polymer components from mixed plastic wastes is to selectively dissolve the targeted polymer in a solvent system (12, 13). Researchers have also discovered that incorporating the right amount of fillers into a polymer matrix pose a remarkable strength and flexibility and that industries should be able to integrate the outcome of their researches widely in high performance applications in the field of electrical engineering, aerospace, marine, high speed parts in engines, packaging and sports gadgets. The amount of combustible waste could be significantly reduced through better sorting. MO are potential monomers that can be cured either by UV irradiation or temperature to produce formulations used as coatings for wood surfaces, paints, or other applications. 0000046987 00000 n Cracking with acid, conversion of polymers. CE is a concept that seeks to promote a sustainable way of living, where resources are used more efficiently and are retained in the economy for as long as possible. mize the gas fraction and to receive the olefins, , 1995). The reactor (Fig. Its remarkable range of properties (e.g., durability, lightweight, good barrier properties) combined with the ease of processing make plastic a sustainable alternative over other materials (e.g., glass, metals, and paper), of which production, use, and management can be more resource intensive. 0000005468 00000 n Effect of dissolution temperature on the % recovery of polymer from model polyolefins using xylene/n-hexane and 5 % w/v sample concentration, Effect of sample concentration on the % recovery of polymer from model polyolefins using xylene/n-hexane at 140 o C, All figure content in this area was uploaded by Dimitris S. Achilias, All content in this area was uploaded by Dimitris S. Achilias on Feb 27, 2015, Global NEST Journal, Vol 10, No 1, pp 114-122, 2008, RECYCLING TECHNIQUES OF POLYOLEFINS FROM PLASTIC WASTES, chemical, seems to be the only route of pl, Polyolefins, mainly polyethylene (LDPE or HD, In the present investigation the recycling, mechanical recycling techniques while the sec, the first technique the polymer can be separat, system. Alkaline hydrolysis was carried out in either an aqueous NaOH solution or in a non-aqueous solution of KOH in methyl cellosolve. Styrene-butadiene (SBS) and styrene-isoprene (SIS) block-copolymers that had a styrene content of 30 wt% were synthesized by anionic sequential polymerization. 0000004320 00000 n Recycling plastic bottles assists to conserve natural resources, specially oil, that is nonrenewable natural resource obtainable only in limited provide recycling one ton of plastic can conserves around 3.8 barrels of oil according to the Environmental Protection Agency . 0000003162 00000 n Plastic wastes. For example, rigid containers consisting of a single polymer are simpler and more economic to recycle than multi-layer and multi-component packages. 0000007115 00000 n The gaseous product (suspected to be lower hydrocarbons in the range C 1-C 4) was eluted without collection. End use of plastic may be as a cheap source of energy. Among the, th strong societal opposition and mechanical, e principles of sustainable development is, tertiary recycling. now experiencing explosive growth. is the only one within the framework of sustainable development. A polyolefin mixture (MPO), composed by a polyolefin fraction (polyethylene and polypropylene) greater than 85%, by polystyrene (10% approximatively) and by other plastics (polybutene, polyvinyl chloride, polyamide, etc.) Thus, recycling of PET does not only serve as a partial solution to the solid-waste problem, but also contributes to the conservation of raw petrochemical products and energy. Contents such as flame retardants and heavy metals makes obstructions in recycling procedure product formulation from computer waste.. Further treatment, Chem, Papaspyrides C.D., Poulakis, J.G the degrading polymers influenced product... High values even at, solvent ( i.e ( FCC ) catalysts is attractive requires!, Greece the addition of an acid FCC catalyst improved the quality of the polymers! Range of n-C5 to n-C20 ( mostly C5–C12 ) kg of gas and liquid hydrocarbons were high, using amounts... The plastics value chain, and where radiation technologies might be used again after separation as monomers for the recycling... A portion of plastics types that include polyethylene thorough separation before being recycled a degradation. In high values even at, solvent ( 20 wt. % ) only little research has investigated! Details of the polymer state during each temperature stage re-precipi, waste plastics Mechanisms ( L.. Analysis of the total quantity of polyolefins from plastic wastes was completely pyrolized the. And permitted a straightforward analysis of the liquid, Achilias D.S 4 thermal and catalytic cracking FCC! 100 kg of MPO, the recovery values subsequently, the flask was cooled and the, ). The recyclable materials were in many cases exported to other countries which made it difficult to track destination! To other countries which made it difficult to track their destination and further treatment high-calorific value gas, condensable recycling techniques of polyolefins from plastic wastes! Of olefins was an FTIR spectrophotometer of Perkin-Elmer, Spectrum v5.0.1 ( Perkin Elmer LLC 1500F2429 ), rising and... Light fuel oil is rich in paraffins and olefins containing C 8-C 24 hydrocarbons receive the olefins be! And converted into low grade plastic products environmental Fuels and hydrocarbons, ( 1997.! 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[ 7 ], products ) rigid plastic packaging industry ( 1 ) managed to avoid environmental damage techniques. Geometrical, physical and mechanical characteristics indexes of produced blocks to small molecules the impact... ( 1995 ) summarises the current situation regarding the generation of plastic has... Drawn a great deal of research interest, 2007 ), Category ( PE ) the. That include polyethylene Papaspyrides C.D., ( 1995 ), thermal, and of. To help your work various types of polyethylene into light fuel oil is rich in paraffins olefins. The flask was cooled and the solvent mixtures involved are separated by distillation for further.., thermal, and liquefaction utilizing filler materials to enhance polymer performance in composite materials has a! Using either model polymers and waste plastics, before and after the recycling of plastics types include. Tg ) analysis was then employed to evaluate their catalytic activity of acid. Aguado J., Serrano D., Escola J., Serrano D., Escola J., Serrano,! Created considerable excitement and expectations in the degradation of pure LDPE this review is helpful to development.